The present disclosure relates to a light-emitting diode display device and a method for manufacturing the same.
There are various technical fields involving mounting micro-articles on a mounting substrate. An example of such fields is the field of light-emitting diode displays. In a light-emitting diode display, a red light-emitting diode functions as a red light-emitting sub-pixel, a green light-emitting diode functions as a green light-emitting sub-pixel, and a blue light-emitting diode functions as a blue light-emitting sub-pixel so that a color image is displayed according to emission states of these three types of sub-pixels.
For example, in a 40-inch diagonal full HD (High Definition) full-color display, the number of pixels in a horizontal direction of a screen is 1920, and the number of pixels in a vertical direction of a screen is 1080. In this case, therefore, the number of the light-emitting diodes mounted is 1920×1080× (the number of the three types of light-emitting diodes, i.e., the red light-emitting diode, the green light-emitting diode, and the blue light-emitting diode, which constitute one pixel) and is thus about 6,000,000. Therefore, as a method for mounting such a vast number of light-emitting diodes on a display substrate, there is a method of forming a light-emitting diode array of a size smaller than a screen size and successively mounting light-emitting diodes on a display substrate from the light-emitting diode array while shifting the positions, i.e., a step transfer method (step mounting method).
Such a step transfer method is disclosed in, for example, Japanese Unexamined Patent Application Publication Nos. 2004-273596 and 2004-281630. In a technique disclosed in these patent application publications, basically, elements are buried in an adhesive layer formed on a surface of a transfer substrate so that the elements partially project from the substrate, and then buried deeply in the adhesive layer using a roller or the like (refer to, for example, paragraphs [0045] to [0048] of Japanese Unexamined Patent Application Publication No. 2004-273596 and paragraphs [0038] and [0046] of Japanese Unexamined Patent Application Publication No. 2004-281630).
As a substrate for manufacturing GaInN-based light-emitting diodes, at present, it is difficult to produce a substrate having a large nominal diameter exceeding 2 inches. As a substrate for manufacturing AlGaInP-based light-emitting diodes, at present, it is difficult to produce a substrate having a large nominal diameter exceeding 3 inches. Thus, a sapphire substrate having a nominal diameter of 2 inches is used for producing blue light-emitting diodes and green light-emitting diodes, and a GaAs substrate having a nominal diameter of 3 inches is used for producing red light-emitting diodes. When a 26-inch diagonal light-emitting diode display is manufactured, blue light-emitting diodes, green light-emitting diodes, and red light-emitting diodes are mounted on a display substrate of a size of 650 mm×550 mm.
As described above, one pixel usually includes three sub-pixels. Therefore, the three types of light-emitting diodes, i.e., red light-emitting diodes, green light-emitting diodes, and blue light-emitting diodes, are moved (e.g., transferred) to a display substrate, and then wiring is formed and drawn by a complicated process, for driving these three types of light-emitting diodes.
It is desirable to provide a method for manufacturing a light-emitting diode display which is capable of manufacturing a light-emitting diode display by a simple process, and a light-emitting diode display manufactured by the method.